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From: Alexander Lyakas <alex.bolshoy@gmail.com>
To: Stuart Yoder <b08248@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: Question about host CPU usage/allocation by KVM
Date: Thu, 19 Apr 2012 21:01:54 +0300	[thread overview]
Message-ID: <CAGRgLy7uxgP+-B-0Oj+_qoAob3xS8x5rb05rE5scE=8Nd9VrCQ@mail.gmail.com> (raw)
In-Reply-To: <CALRxmdB-RWuMw-c4PC7fh2nYZG4iiWL7hVOzvTVsYgsobwwthg@mail.gmail.com>

Hi Stuart,
I have been doing some experiments, and I noticed that there are
additional QEMU threads, besides the ones reported by "info cpus"
command. In particular, the main QEMU thread (the one whose LWP is the
same as its PID), also consumes significant CPU time. Is this
expected?

Alex.


On Wed, Apr 18, 2012 at 8:24 PM, Stuart Yoder <b08248@gmail.com> wrote:
> On Tue, Apr 17, 2012 at 4:54 PM, Alexander Lyakas
> <alex.bolshoy@gmail.com> wrote:
>> Greetings everybody,
>>
>> Can anybody please point me to code/documentation regarding the
>> following questions I have:
>>
>> - What does it actually mean using "-smp N" option, in terms of CPU
>> sharing between the host and the guest?
>> - How are guest CPUs mapped to host CPUs (if at all)?
>
> Each guest CPU (vcpu) corresponds to a QEMU thread.
> You can see the thread ids in QEMU with "info cpus" in the
> QEMU monitor.
>
> Since a vcpu is a thread you can apply standard Linux
> mechanisms to managing those threads-- CPU affinity, etc.
>
> Stuart

  parent reply	other threads:[~2012-04-19 18:01 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-17 21:54 Question about host CPU usage/allocation by KVM Alexander Lyakas
2012-04-18 15:58 ` Avi Kivity
2012-04-18 17:24 ` Stuart Yoder
2012-04-18 20:55   ` Alexander Lyakas
2012-04-19 18:01   ` Alexander Lyakas [this message]
2012-04-20 15:01     ` Brian Jackson
2012-04-20 23:12       ` Shergill, Gurinder

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